Flow control valve



Jan. 23, 1962 E. w. STEFFENS 3,017,903

FLOW comm. VALVE Filed Aug. 17, 1960 BE 1 7,903 Patented Jan. 23,1962

3,017,903 FLOW CONTROL VALVE Eugene Walter Stefiens, 420 Lake Ave., St. Louis 8, Mo. Filed Aug. 17, 1960, Ser. No. 50,210 It Claim. (Cl. 138-45) This invention relates to valves, and more particularly to a valve such as may be used to control the rate of flow of refrigerant in a refrigeration system.

This application constitutes a co-ntinuation-in-part of application Serial No. 848,759, filed October 26, 1959, now abandoned In a refrigeration system, a refrigerant is constantly passing through an evaporation and condensation cycle to withdraw heat from the system. The rate of refrigeration is dependent on, among other things, the rate of refrigerant passing through the system, which means that the flow of the refrigerant must be controlled to maintain a desired temperature in the refrigeration system. Accordingly, among the several objects of this invention may be noted the provision of a novel valve particularly for controlling the flow of refrigerant in a refrigeration system (though not limited to such use) adapted to act in response to change in temperature of the evaporation section of the system to change the rate of flow (i.e., to in crease the rate of flow on increase of temperature and to decrease the rate of flow on decrease of temperature); and the provision of such a valve which is of simplified economical construction and reliable in operation. Other objects and features will be in part apparent and in part pointed out hereinafter.

The invention accordingly comprises the constructions hereinafter described, the scope of the invention being indicated in the following claim.

In the accompanying drawings, in which one of various possible embodiments of the invention is illustrated:

FIG. 1 is a view in side elevation of a valve of this invention;

FIG. 2 is a transverse section of the valve taken on line 22 of FIG. 1;

FIG. 3 is a longitudinal section of the valve taken on line 3-3 of FIG. 2; and

FIG. 4 is a longitudinal section of the valve taken on line 44 of FIG. 2,

Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.

Referring to the drawings, a flow control valve of this invention is shown to comprise a pair of end heads, each designated l, which may be made of brass, for example. Each end head has a threaded extension 2 for securing the valve in a refrigerant line, and a central bore 3. A flexible tubular member or conduit 4, which may be made of a material such as thin corrosion-resistant spring steel stock, extends between the end heads. This member is circular in cross section at the ends thereof, and of elliptical cross section in the central portion thereof as indicated at 4a. The ends of the flexible tubular member or conduit 4 have a sealing fit in the bores 3 of each of the end heads 1 and may be brazed therein. A flexible tubular member 5, which may also be made of thin corrosionresistant spring steel stock, and which is elliptical in cross section throughout its length has its ends seated on elliptical shoulders 6 formed on the insides of end heads 1. Member surrounds conduit 4, and may have its ends brazed on shoulders 6. A relatively rigid cylindrical casing 7, which may be made of copper, for example, extends between end heads 1 surrounding member 5. The end heads have cylindrical peripheral portions or shoulders 8, on which the ends of casing 7 have a sealing fit, being brazed thereto, for example. It will be seen that a chamber 9 is formed between the flexible conduit 4 and the flexible tubular member 5, the end heads 1 constituting the ends of the chamber. A chamber 10 is also formed between the tubular member 5 and the casing 7, end heads 1 constituting the ends of this chamber.

A refrigerant 11 such as dichlorodifluoromethane (sold under the trade name Freon 12) is sealed in chamber 10. It will be understood that this particular refrigerant is in the gaseous state, and is adapted to exert pressure on elliptical member 5. Other suitable fluids may be used in chamber 10.

The parts are assembled with the major axis of the elliptical cross section of portion 4a of conduit 4 coincident with the minor axis of the cross section of member 5. The inside of elliptical member 5 is contiguous to the outside of elliptical portion 4a of conduit 4 at points on the minor axis of elliptical member 5 and the major axis of elliptical portion 4a of conduit 4. Pressure exerted by gas 11 on the outside of tubular member 5 will cause the central pontion of the latter to flatten, thereby decreasing the major axis of portion 4a of conduit 4 and increasing its minor axis, with the result that the cross sectional area of portion 4a is increased and the flow capacity of conduit 4 is increased.

A valve as above described may be placed in the refrigerant line of a refrigeration system to act in response to change in temperature of the evaporating section of the refrigeration system. Upon increase in temperature, heat is transferred to the gas 11 within chamber 10, causing expansion of the gas. This pressure causes the central portion of elliptical member 5 (which is flexible) to flatten, thereby enlarging the cross sectional area of the central portion 4a of conduit 4 (making it more nearly circular), and thereby increasing the rate of flow through conduit 4. On decrease of temperature, the gas pressure decreases, elliptical member 5 expands due to its inherent resilience, and the central portion 4a automatically flattens due to its inherent resilience, thereby constricting conduit 4 and decreasing the rate of flow therethrough.

While the chamber 10 is shown sealed, it is contemplated that a capillary tube having one end in communication with chamber 10 and the other end attached to a bulb containing a gas capable of expansion could be used without departing from the spirit of the invention. The bulb could be placed in the evaporating section of the refrigeration system and the valve could be then placed away from the evaporating section of the refrigeration system where no heat is involved. The same effect on the flow capacity of the valve would result from such a construction.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim:

A valve comprising a casing, end heads at the ends of the casing, each end head having an axial passage, a conduit extending between said end heads and having its ends sealed in said passages, said conduit having a deformable central portion of elliptical cross section, a deformable tubular member of elliptical cross section surrounding said conduit extending between said end heads and having its ends sealed thereto, the major axis of the elliptical cross section of the central portion of the conduit being substantially coincident with the minor axis of the elliptical cross section of said tubular member and the inside of the latter being contigmous to the outside of the central portion of the conduit at points on the minor axis of the tubular member and the major axis of the central portion of the conduit, and a fluid confined in the space between the tubular member and easing.

References Cited in the file of this patent UNITED STATES PATENTS 2,241,086 Gould May 6, 1941 2,735,642 Norman Feb, 21, 1956 2,958,502 Grigsby Nov. 1, 1960 FOREIGN PATENTS 269,907 Germany Feb. 3, 1914 

